Water-soluble contact lens care product

ABSTRACT

A water-soluble, solid contact lens care agent ( 1 ) having at least a first ( 2 ) and a second ( 3 ) compartment containing within the first compartment ( 2 ) at least one agent, in particular a protease, for removing or supporting the cleaning of metabolic deposits on a contact lens and within the second compartment ( 3 ) at least one agent being capable of neutralizing a contact lens disinfecting solution, characterized in that the first compartment ( 2 ) is dissolved faster within the contact lens disinfecting solution than the second compartment ( 3 ) and both compartments ( 2, 3 ) are simultaneously subjectable to the contact lens disinfecting solution.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Subject matter of the present invention is a water-soluble, solidcontact lens care agent.

2. The Prior Art

Contact lenses are much in demand with individuals suffering fromametropia. Still, one problem with the use of contact lenses is thecorrect care thereof. There is known a multitude of different systemshaving essentially in common that a disinfection of the contact lens iseffected after wearing the contact lens, usually during the night, wheredisinfection is effected by chemicals which have to be neutralizedsubsequently due to the aggressive character thereof. For this purpose amultiplicity of care agents has been successful on the market, e.g., anaqueous hydrogen peroxide solution as disinfecting solution which isneutralized or decomposed by subsequent steps. To this end, severalsystems such as the catalytic decomposition on precious metal surfaces,the enzymatic decomposition using, e.g., catalase, and the chemicalneutralization by reduction of the hydrogen peroxide by sodiumthiosulfate are known in the art. The problem of removing metabolicdeposits, in particular protein deposits on the lenses or within thelens material, has in principle been solved in the art as well. Forthis, e.g., agents containing protease are added during a preliminarycleaning step. In particular, subtilisin has to be mentioned as aprotease removing any protein deposits within the matrices of softcontact lenses. The state of the art is represented by EP 0 219 220.There, a combined contact lens care agent is described which bothdisinfects and cleans the contact lenses. In this case, a solution ofhydrogen peroxide and a protease being active in a peroxide-containingsolution effects disinfection. As a suitable protease subtilisin ismentioned.

Removing any metabolic deposits, in particular protein deposits, withinthe contact lens matrices is extremely important as these depositsresult in changes of the lens matrix including changes of the opticalproperties and the generation of inflammations.

Although various systems have been available in the market, caringespecially for soft contact lenses seems to be so complicated thatrecently so-called one-way contact lenses have been marketedincreasingly. Here, cleaning and disinfecting is no longer in the foreas the contact lenses are simply disposed after a certain wearing time.On the other hand, this results in the fact that only ready-made,mass-produced articles can be offered as any individual adaption of thecontact lens is too costly, so that an individually adapted one-way lenswill be unattainable. However, when dispensing with individual adaptionspatients are provided with contact lenses lacking optimal properties, sothat such a way of proceeding is not advisable from the physiologicalpoint of view.

The state of the art is especially detrimental in that proteases areusually employed in a separate cleaning step which is arranged prior tothe disinfection. Because of this a high willingness of the user toperform the cleaning and disinfection correctly is demanded. Afterperforming the cleaning using proteases, this protease solution usuallyis discarded and subsequently a separate disinfection phase isperformed. This two-stage process is often considered to be cumbersomeby users and promotes an improper mode of behavior due to a negligentuse. Thus, for example, it may happen that the disinfecting step isforgotten and the lens is put on directly from the protease solution. Ina different method a protease is added to the disinfecting solution,said protease, however, being added in such a high amount that theprotease has to be eliminated by a physiological solution after thecleaning step. Otherwise, too much protease would remain within thecontact lens matrix possibly resulting in irritations on the user's eye.

SUMMARY OF THE INVENTION

Consequently, it is the object of the present invention to providesystems which allow contact lenses to be cleaned and disinfected in asimple way.

Surprisingly, the object of the present invention is achieved in asimple way by a contact lens care agent having the features of theinvention.

The contact lens care agent according to the invention has at least afirst and a second compartment. The first compartment contains at leastone agent, in particular metabolic protease, for removing or supportingthe cleaning of protein-like deposits on a contact lens. The at leastsecond compartment contains at least one agent being capable ofneutralizing a contact lens disinfecting solution. Here, it is essentialfor the invention that the first compartment will dissolve quicker in acontact lens disinfecting solution than the second compartment. Bothcompartments can be subjected to the contact lens disinfecting solutionat the same time. Proteases, in particular proteases of the serine type,are suited for the metabolic deposits removing agent. An enzyme classknown as alkaline proteases, generally as subtilisin, is particularlypreferred. Suitable enzymes have been characterized in EP 0 219 220.

The second compartment contains a contact lens disinfectant, wherein inthe case of an aqueous hydrogen peroxide solution enzymes such ascatalase or chemicals such as sodium dithionite are to be mentioned.

Preferably, the contact lens care agent according to the inventionconsists of a fist compartment and a second compartment. In oneembodiment the first compartment encloses the second one completely.Preferably, however, the first compartment is enclosed by the secondcompartment not completely or only partially on all sides. Thereby, asimultaneous access of the disinfecting solution to the compartments isenabled. In a particular embodiment the first embodiment encloses thesecond compartment at least concentrically. In another embodiment of thecontact lens care agent according to the invention said agent forms aformed piece having two axes being perpendicular to each other, whereinthe first compartment is located around a first axis and the secondcompartment is located around a second axis. Preferably, thecompartments are arranged rotationally symmetrical around one axis.

The disinfectant contacts the compartments and dissolves the firstcompartment quicker than the second compartment. The dissolution of thefirst compartment can be accelerated by additives. As additives inparticular substances forming a readily soluble matrix or mixtures ofsubstances generating effervescence in aqueous solution may be used.Especially preferred is the use of additives contributing to theformation of an isotonic solution subsequent to the dissolution of thecompartments.

The second compartment may contain additives retarding a dissolution ofthe second compartment. This can be realized, e.g., by using substancesor mixtures of substances which are more sparingly soluble than thosebeing used in the first compartment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a first embodiment of the invention in which atoroidal-shaped compartment surrounds a cylindrical-shaped compartment;

FIG. 2 shows a second embodiment, wherein the first compartment is boredthrough centrically and this bore is filled with the second compartment;and

FIG. 3 shows another embodiment, wherein the first compartment enclosesthe second one completely.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

FIG. 1 illustrates a preferred embodiment of the contact lens care agentaccording to the invention. Here, a formed piece configured essentiallycylindrically is the second compartment 3 containing subtilisin asprotease. Said essentially cylindrical formed piece 3 containingsubtilisin compressed within a usual tablet matrix is partiallyencompassed by the first compartment 2 having a toroidal shape, in thecenter of which the essentially cylindrical formed piece 3 of the firstcompartment is located.

FIG. 2 illustrates another embodiment, wherein the first compartment 2is bored through centrically and said bore is filled with the secondcompartment 3 so that the second compartment is partially encompassed.

The contact lens care agent is a formed piece having two axes V and Hbeing perpendicular to each other, wherein the first compartment (2) islocated around the first axis H and the second compartment (3) islocated around the second axis V.

FIG. 3 illustrates another embodiment, wherein the first compartment 2encloses the second one 3 completely.

Initially, the user fills the aqueous disinfecting solution, preferablya 3% hydrogen peroxide solution, into a cleaning device known per se andadds the contact lens care agent according to the invention and thecontact lenses to be cleaned and disinfected. The disinfecting solutionwill dissolve the compartment containing subtilisin so that the removalof any deposits existing on the lens begins. Simultaneously, the contactlens is disinfected by the action of the disinfectant H₂O₂. Depending onthe embodiment also the second compartment, containing the agentneutralizing the disinfectant is dissolved more or less simultaneously.Due to the higher dissolution rate of the first compartment said firstcompartment will be dissolved completely when the second compartment hasdissolved only partially within the disinfecting solution. Then, thecatalase contained within the second compartment is further graduallydissolved into the disinfecting solution so that the catalase willincreasingly cause the decomposition of the hydrogen peroxide withinsaid compartment.

The contact lens care agent according to the invention provides a novelcontact lens care system. Namely, on consultation with the contact lensfitter the user can define an individual cleaning procedure suited tothe user's situation. Thus, e.g., if only moderate contaminations arepresent it is possible to perform the conventional disinfection on twosuccessive days, whereas the contact lens care agent according to theinvention is added at the third day in order to avoid performing theprotein cleaning every day. Likewise, if heavier contaminations arepresent, removal of protein deposits can be effected on every other dayusing the contact lens care agent according to the invention. Thecontact lens care agent according to the invention is administered,e.g., in the form of blister packs, wherein in that case also tabletscontaining disinfectant neutralizers are offered. For example, there canbe offered a blister pack offering, beginning with the contact lens careagent according to the invention in the form of tablets, e.g., twotablets which do not contain the agent, in particular the protease, forremoving metabolic deposits, e.g., protein deposits. Only on the fourthday the blister pack will provide the contact lens care agent accordingto the invention, again followed by two tablets containing only theneutralizer.

The contact lens care agent according to the invention may contain thematerials contained within the compartments also in the form ofgranulate, the compartments being designed, e.g., as capsules.

It may be preferred to perform the removal of the hydrogen peroxide notcompletely by defining the container volumes variably. With that, aresidue of hydrogen peroxide will remain in the storage solution orcleaning solution. The advantage of the variability of the hydrogenperoxide volume to be employed is that during a longer storage periodcorrespondingly more H₂O₂ containing solution can be provided so thatdecomposition will occur not completely and a residual content of H₂O₂remains within the solution in order to provide a persistent bactericideand/or bacteriostatic environment within the solution. In particular,this residual content of hydrogen peroxide can be up to 0.8% by weightand, if required, less, e.g., up to 0.2% by weight. This offers theadvantage that in particular during a longer storage of the lens withinthe storage solution there will be no subsequent microbic contaminationas a continued bactericide and/or bacteriostatic environment will bepresent.

The agent can be adjusted such that there remains no or only a very lowvalue of stimulus which remains controllable even with a very pronouncedsensitivity of the eyes by a very short-time rinsing using appropriatecommercial sodium chloride rinsing solutions.

What is claimed is:
 1. A water-soluble, solid contact lens care agent(1) comprising at least a first (2) compartment and a second (3)compartment containing within the first compartment (2) at least oneagent for removing or supporting the cleaning of metabolic deposits on acontact lens and within the second compartment (3) at least one agentbeing capable of neutralizing a contact lens disinfecting solution,wherein the first compartment (2) is dissolved faster within the contactlens disinfecting solution than the second compartment (3), and bothcompartments (2, 3) are simultaneously subjectable to the contact lensdisinfecting solution due to the fact that the compartment (2) partiallyencompasses the second compartment (3).
 2. The contact lens care agentaccording to claim 1, wherein two compartments (2, 3) are provided. 3.The contact lens care agent according to claim 1, wherein thedissolution of the first compartment (2) within the disinfectingsolution is accelerated by additives.
 4. The contact lens care agentaccording to claim 1, wherein the dissolution of the second compartment(3) within the disinfecting solution is retarded by additives.
 5. Thecontact lens care agent according to claim 1, wherein the agent forneutralizing a contact lens disinfecting solution is present only insuch an amount that a partial neutralization of the contact lensdisinfectant takes place.
 6. The contact lens care agent according toclaim 1, wherein the first compartment (2) contains subtilisin and thesecond compartment (3) contains catalase.
 7. The contact lens care agentaccording to claim 1, wherein the at least one agent for cleaning ofmetabolic deposits comprises a protease.
 8. A water-soluble, solidcontact lens care agent (1) comprising at least a first (2) compartmentand a second (3) compartment containing within the first compartment (2)at least one agent for removing or supporting the cleaning of metabolicdeposits on a contact lens and within the second compartment (3) atleast one agent being capable of neutralizing a contact lensdisinfecting solution, wherein the first compartment (2) is dissolvedfaster within the contact lens disinfecting solution than the secondcompartment (3), and both compartments (2, 3) are concentricsimultaneously subjectable to the contact lens disinfecting solution dueto the fact that the first compartment (2) partially encompasses thesecond compartment (3).
 9. A water-soluble, solid contact lens careagent (1) comprising at least a first (2) compartment and a second (3)compartment containing within the first compartment (2) at least oneagent for removing or supporting the cleaning of metabolic deposits ona-contact lens and within the second compartment (3) at least one agentbeing capable of neutralizing a contact lens disinfecting solution,wherein the first compartment (2) is dissolved faster within the contactlens disinfecting solution than the second compartment (3), and bothcompartments (2, 3) are simultaneously subjectable to the contact lensdisinfecting solution due to the fact that the first compartment (2)partially encompasses the second compartment (3); and the contact lenscare agent is a formed piece having two axes being perpendicular to eachother, wherein the first compartment (2) is located around a first axisand the second compartment (3) is located around a second axis.